DE60314885T2 - CRANKSHAFT FOR A VEHICLE COMBUSTION ENGINE - Google Patents

Description

These The invention relates to a crankshaft for a V-type internal combustion engine.

In order to better understand the state of the art in this field and the problems associated therewith, it is first to be understood in connection with 1 from the accompanying drawings, taken from US Pat. No. 4,730,512, a known crankshaft will be described.

This patent describes a crankshaft, generally the reference numeral 1 carries, for a V-6 cylinder internal combustion engine. In particular, the crankshaft points 1 four shaft journals that (in 1 seen from left to right) with the reference numbers 21 to 24 are provided, and six crank pins on which the reference numerals 41 to 46 wear. The shaft journals and the crank pins are connected by a series of nine crank webs with the reference numerals 61 to 69 are provided, wherein the first crank arm 61 , the second crank arm 62 , the eighth crank arm 68 and the ninth crank arm 69 with integrated counterweights 61 ' . 62 ' . 68 ' respectively. 69 ' are provided to the imbalance of the crankshaft 1 compensate.

The main problem with a prior art structure as described above is that to compensate for the unbalance of the crankshaft by means of counterweights formed in common with the shaft, the outer crank webs 61 and 69 each end pair of the crank webs 61 - 62 and 68 - 69 that is between the two first shaft journals 21 - 22 or the two last shaft journal 23 - 24 lie, must be made much thicker than the corresponding inner crank webs 62 or 68 , This greater thickness implies a substantial increase in the length X of the two end spans of the crankshaft, that is, the spans between the pairs of journals 21 - 22 and 23 - 24 , opposite to the length Y of the center span extending between the shaft journals 22 and 23 extends, whereby the bending stress increases in those areas in which the crank webs 62 and 68 with the adjacent pairs of crank pins 41 - 42 respectively. 45 - 46 are connected.

The Thickness of these critical areas can be known to be increased for their resilience To improve against stress, but this would be another Increase in total length the crankshaft and thus the engine lead.

Around to compensate for the unbalance of the crankshaft of a V-type internal combustion engine, without the axial dimension of the Endstützweiten is increased, For example, US Pat. No. 5,000,141 provides a crankshaft, as well has been described above, in which the two pairs of axially completely Outside lying crank webs have substantially the same thickness, with two more counterweights outside the axially outermost one Shafts are arranged, i. inside a pulley or a flywheel coaxially attached to the crankshaft are.

These known solution however, requires the use of a pulley and a flywheel, specially adapted to receive a counterweight each, whereby these components have a more complicated shape, through the costs rise.

One The object of the present invention is therefore to provide a Crankshaft for to deliver a V-type internal combustion engine, the crankshaft being a pair has counterweights outside the axially outermost Shaft pins are arranged, has a simpler structure and cheaper to manufacture than this in the above-mentioned state the technique is the case.

This The subject is completely with the invention reached a crankshaft having those features that in the claim 1 are fixed.

Further advantageous features are defined in the subclaims.

The Invention will now be described by way of example and in connection with the accompanying drawings, in which shows:

1 the simplified side view of a crankshaft according to the prior art, as described above, partially in section through an axial plane; and

2 the simplified side view of a crankshaft according to the present invention.

In connection with 2 in which parts and elements, the parts and elements of 1 are identically or equivalently provided with the same reference numerals, a crankshaft for a V-6 cylinder internal combustion engine generally bears the reference numeral 1 , In the drawings, from left to right, a first shaft journal 21 , a first crank arm 61 , a first crankpin 41 , a second crank arm 62 , a second crankpin 42 , a third crank arm 63 , a second shaft journal 22 , a fourth crank arm 64 , a third crankpin 43 , a fifth crank arm 65 , a fourth crankpin 44 , a sixth crank arm 66 , a third shaft journal 23 , a seventh crank cheek 67 , a fifth crankpin 45 , an eighth crank arm 68 , a sixth crankpin 46 , a ninth crank arm 69 and finally a fourth shaft journal 24 has.

As in the prior art described above, those elements form the crankshaft relative to the middle element, ie the fifth crank arm 65 , are arranged symmetrically, pairs of equal thickness. To compensate for the imbalance of the crankshaft, additionally form the first crank arm 61 , the second crank arm 62 , the fifth crank arm 65 , the eighth crank arm 68 and the ninth crank arm 69 appropriate integrated counterweights 61 ' . 62 ' . 65 ' . 68 ' and 69 ' ,

In accordance with the above introduced Terminology is attached in the remaining description and in the attached claims the term "span" is used to mean that he designates a part of the crankshaft that is between two adjacent ones Shaft journal lies. additionally become the two spans, which are arranged at one of each axial end of the shaft, referred to as "Endstützweiten", while those Spans that axially between the end spans are referred to as "intermediate support widths".

At the in 2 example shown are the two end support widths of the crankshaft 1 between the pairs of shaft journals 21 - 22 respectively. 23 - 24 while the only intermediate span between the shaft journals 22 and 23 lies.

To avoid any increase in the stresses in those areas where the crank webs 62 and 68 with the pairs of adjacent crank pins 41 - 42 respectively. 45 - 46 are connected, in accordance with a first essential feature of the invention, the axial dimensions of the two outermost crank webs 61 and 69 suitably reduced, being substantially equal to the dimensions of the adjacent crank webs 62 and 68 be made, whereby the two end support widths of the shaft have the same axial length Y as the intermediate support width.

To ensure that the unbalance of the crankshaft 1 regardless of the reduction in the axial dimensions of the first and ninth crank arms 61 and 69 is balanced, the crankshaft in accordance with another essential feature of the invention, two additional counterweights 71 and 72 on that end outside of the corresponding shaft journal 21 and 24 are arranged. The axial dimensions of the counterweights 71 and 72 are with the dimensions of the above-mentioned crank webs 61 . 62 . 68 and 69 comparable.

To the length of the crankshaft 1 Finally, seats are in accordance with another aspect of the invention seats 80 (in 2 simplified) for attachment of the flywheel (not shown) directly in that counterweight 72 trained, which is directed to the flywheel.

• – die Länge der Kurbelwelle gleichmäßig über die verschiedenen Stützweiten verteilt werden, wodurch sicher gestellt wird, dass die Welle immer ausgewuchtet ist;
• – durch die Herabsetzung der Länge der Kurbelwelle die Beanspruchung auf die Endstützweiten der Kurbelwelle herabgesetzt werden;
• – die Länge der Kurbelwelle begrenzt werden, indem die Sitze für die Befestigung des Schwungrads direkt im ganz außen liegenden Gegengewicht ausgebildet werden, das am nächsten zum Schwungrad angeordnet ist; und
• – im Vergleich mit Aufbauten gemäß dem Stand der Technik bei einer Kurbelwelle mit den gleichen axialen Abmessungen eine Reduktion der Masse erreicht werden.

With the proposed structure can be advantageous:

• - The length of the crankshaft are distributed evenly over the different spans, ensuring that the shaft is always balanced;
• - By reducing the length of the crankshaft, the stress on the Endstützweiten the crankshaft are reduced;
• - The length of the crankshaft are limited by the seats for mounting the flywheel are formed directly in the very outer counterweight, which is located closest to the flywheel; and
• - In comparison with structures according to the prior art in a crankshaft with the same axial dimensions, a reduction of the mass can be achieved.

Even though the invention described in connection with a V-6 cylinder engine was, is for It will be apparent to those skilled in the art that they are equally applicable to any V-type engine independently It can be applied to how large the number of its cylinders is.

Claims (3)

Crankshaft ( 1 ) for an internal combustion engine, the crankshaft comprising: a first pair of shaft journals ( 21 . 22 ) axially delimiting a first end span; a second pair of shaft journals ( 23 . 24 ) axially delimiting a second opposite end span; at least one intermediate span axially between the first and second end span; a first crank arm ( 61 ), which are connected to the outer shaft ( 21 ) of the first pair of shaft journals ( 21 . 22 ), and a second crank arm ( 69 ), which are connected to the outer shaft ( 24 ) of the second pair of shaft journals ( 23 . 24 ), wherein the axial dimensions of the first and the second crank arm ( 61 . 69 ) are formed so that the end support widths have substantially the same length (Y) as the at least one intermediate support width; a first and a second counterweight ( 61 ' . 69 ' ) on the first and on the second crank arm ( 61 . 69 ) are provided to the unbalance of the crankshaft ( 1 ) compensate; and a third and a fourth counterweight ( 71 . 72 ), which are outside the corresponding Endwellenzapfen ( 21 . 24 ) are arranged; characterized in that the seats ( 80 ) in a counterweight ( 72 ) of the third and fourth counterweights ( 71 . 72 ) are adapted to attach a flywheel directly to this counterweight. Crankshaft according to claim 1, wherein the third and the fourth counterweight ( 71 . 72 ) have substantially the same axial dimension. Crankshaft according to claim 2, wherein the axial dimensions of the third and the fourth counterweight ( 71 . 72 ) substantially equal to the dimension of the first and the second crank arm ( 61 . 69 ).